Update pypdf requirement from ==6.3.* to ==6.4.* (#5659)

Updates the requirements on [pypdf](https://github.com/py-pdf/pypdf) to permit the latest version.
- [Release notes](https://github.com/py-pdf/pypdf/releases)
- [Changelog](https://github.com/py-pdf/pypdf/blob/main/CHANGELOG.md)
- [Commits](https://github.com/py-pdf/pypdf/compare/6.3.0...6.4.0)

---
updated-dependencies:
- dependency-name: pypdf
  dependency-version: 6.4.0
  dependency-type: direct:production
...

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pyproject.toml

@@ -81,7 +81,7 @@ dependencies = [
   "pycountry",
   "pycparser==2.23",
   "pycryptodome==3.23.*",
-  "pypdf==6.3.*",
+  "pypdf==6.4.*",
   "python-bidi==0.6.*",  # Support for Arabic in reportlab
   "python-dateutil==2.9.*",
   "pytz",